1. Field of the Invention
The invention relates to a puerarin derivative and preparation method and use thereof, and more particularly to a 7,2″-dehydrate puerarin and its salts, as well as to preparation method, and use thereof.
2. Description of the Related Art
Puerarin is an isoflavone glycoside extracted from roots of such legumes as kudzu and Pueraria thomsonii. Studies have shown that puerarin can eliminate free radicals, reduce serum cholesterol, and resist against coagulation and allergy. In clinic, puerarin is used for treatment of coronary heart diseases, angina pectoris, myocardial infarction, sudden deafness, and alcoholism.
With so many above-mentioned pharmacological activities, puerarin and derivatives thereof have aroused more and more attention. However, oral administration of puerarin has poor absorption and bioavailability, thereby resulting in a limited application. A conventional dosage form of puerarin for clinical application is injections, but the solubility and bioavailability thereof still need to be improved. To achieve this, structural modification or special formulations of puerarin are being developed. For example, acetylated and triphenylmethylated puerarin significantly improves the blood flow of rabbit eyes. The water-solubility of glycosylated puerarin has been improved greatly. 7-acetylsalicylic acyl puerarin has significant dose-dependent inhibition (IC50=0.91 mmol/L) on platelet aggregation in vitro, and the inhibition is obviously stronger than that achieved by equivalent amount of aspirin or puerarin.
Studies have shown that phenolic hydroxyl of C-glycosylflavones reacts with a hydroxyl of a glycosyl unit thereof intramolecularly to yield a dehydrated derivative with strong bioactivity. In the prior art, no 7,2″-dehydrate puerarin and derivatives thereof has been disclosed.